This invention relates to the use of Tri-methyl PG-F.sub. 2a and its derivatives (I) in the treatment of glaucoma and ocular hypertension. ##STR1##
wherein R.sup.1 is hydrogen, a cationic salt moiety, a pharmaceutically acceptable amine moiety or a pharmaceutically acceptable ester moiety derived from the corresponding alcohol; and R.sup.2 is hydrogen or a pharmaceutically acceptable ester moiety derived from the corresponding carboxylic acid.
Natural prostaglandins are known to lower intraocular pressure (IOP) after topical ocular instillation, but can cause an inflammatory response. Many synthetic prostaglandins have been observed to lower intraocular pressure, but most such compounds also produce the described inflammatory response. Unexpectedly, the 11-alpha methyl group on an E-series prostaglandin analog was shown to essentially eliminate the inflammatory response but maintain a reasonable level of IOP reducing activity. Since it has also been shown that F-series prostaglandins have a greater potency for IOP reduction than E-series prostaglandins, the extension of the utility of the 11-alpha methyl group is reasonable and appropriate. Compounds of I are known.